1. Field of the Invention
The present invention relates to an apparatus for measuring a specific molecule included in a specimen and in particular to an apparatus and a method for reverse iontophoresis configured to extract the specific molecule electrically.
2. Description of the Related Art
Measuring blood sugar is a representative example for measuring a specific molecule concentration included in a specimen and especially in a living body. An existing method for measuring blood sugar is as follows. At first, blood is collected from vein with a syringe or by pricking part of the body with a needle and squeezing the body part to collect a blood sample. The collected blood is deposited on an optical sensor to react with pigments and enzymes as catalysts. Thereafter, by measuring absorbance of the reacted solvent, a concentration of the blood sugar included in the specimen is obtained as disclosed in Guilbault et al., “Advances in Biosensors” JAI Press, 1991, Vol. 1, pp 258-289. However, the existing method for measuring blood sugar using the syringe causes injury and pain.
On the other hand, an iontophoresis method recently became wide spread. An ionized molecule or a water-soluble molecule is introduced into the living body through the skin by iontophoresis as disclosed in published Japanese Patent Application H11-76428. In addition, a reverse iontophoresis method has also been studied recently. By the reverse iontophoresis method, the specific molecule is extracted from the living body through the skin with an electric current. Therefore, applying the reverse iontophoresis method to extract glucose from the living body without injury was attempted. However, the amount of extracted glucose by the reverse iontophoresis method is too small to analyze molecular concentration.